According to the Centers for Disease Control and Prevention, since the human papillomavirus (HPV) vaccine was introduced in the United States in 2006, HPV infections that cause most HPV-related cancers and genital warts have decreased by 88% among teenage girls and 81% among young adult women. Now, a retrospective cohort study further investigating the efficacy of the vaccine in the prevention of HPV-related cancers has found evidence of its benefit in the prevention of several types of malignancies and premalignant dysplasia caused by HPV. The study by DeKloe et al will be presented during the 2024 ASCO Annual Meeting (Abstract 10507).
Study Methodology
The researchers conducted a large retrospective cohort study using a patient population between the ages of 9 and 39 years selected from TriNetX, a health research network. The patients were selected based on medical encounters where any vaccine was administered between January 1, 2010, and December 31, 2023. The patients were divided into two cohorts: those vaccinated for HPV at least 5 years prior and those with no history of HPV vaccination.
Outcomes were the development of malignancy at the following sites: head and neck, cervix, anus and anal canal, penis, vulva, and vagina. Patients with no prior history of cervical dysplasia undergoing Papanicolaou smear were observed for atypical cytology. Propensity score matching was performed to match cohorts for age, race/ethnicity, tobacco use, and body mass index.
Results
The researchers found that male individuals vaccinated for HPV (n = 760,540) had decreased odds of developing HPV-related cancers compared to those who were unvaccinated (odds ratio [OR] = 0.46, 95% confidence interval [CI] = 0.29–0.72, P = .001); this was primarily driven by a significant reduction in head and neck cancer (OR = 0.44, 95% CI = 0.26–0.73, P = .0016). Female individuals vaccinated against HPV (n = 945,999) had lower odds for cervical cancer (OR = 0.71, 95% CI = 0.52–0.96, P = .027) and HPV-related cancers overall (OR = 0.73, 95% CI = 0.57–0.94, P = .013) than those who were unvaccinated.
The odds of head and neck cancer (OR = 0.67, 95% CI = 0.42–1.1, P = .10) and vulvar/vaginal cancer (OR = 1.67, 95% CI = 0.81–3.41, P = .16) were not significantly different in vaccinated female individuals compared to the controls. Vaccinated female individuals were less likely to develop high-grade squamous intraepithelial lesions (OR = 0.44, 95% CI = 0.30–0.65, P < .0001), and carcinoma in situ (OR = 0.422, 95% CI = 0.25–0.72, P = .002).
Conclusions
The study authors concluded that the results suggest early evidence of efficacy of the HPV vaccine in preventing the development of several types of malignancies and premalignant dysplasia caused by the human papillomavirus.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.
